I suppose the supplemental question here should be, are we talking quality or quantinty?
If we're talking quantity, I'd say I have a well, to be blunt mediocre collection.
But if we wish to talk quality. Well, as an example, every set from Stormfront to Undaunted contains every holo (and reverse) every rare (and reverse) every uncommon (and reverse) every common (and reverse) full Prime, Legend, Lv X and Shiny from the apporpriate sets, the Alph Litographs, Shining Gyarados from HGSS, the theme deck alternates, the Raichu and Gyarados (holo and non) from the HGSS Trainer Kit. Every promo released except for the cards obtained from going to World Championship tournaments.
Sets prior to Stormfront have all holos and rares (including reverse) with uncommons and commons about seventy percent. Every Level X, Shiny, EX, Stars. Every promo except the Trainers from the World Championships.
The earlier sets. Base Set is 1st edition shadowless and regular, Jungle is 1st Edition and regular, plus the holos that had no jungle symbol. Fossil is 1st Edition and regular. The Neo Genesis and Neo Discovery (with the Japanese Beedrill holo and Dark Raichu white star holo) are full 1st edition and regular. Misdreavous and Celebi are the only cards I have from Neo Revelations that are not 1st edition, and I have the Aerodactyl, Celebi, Kingdra and Starmie Japanese holos from that set. Neo Destiny has all Holos, Rares, and Shiny Pokemon 1st edition and regular.
Team Rocket, Gym Hero, and Gym Challenge is complete, but is scattered between regualar and 1st edition.
Legendary is pretty decent too, all holo and reverse holo, missing half the regular rares but have all the reverse holos. Not sure about the ratios for the commons/uncommons. I also have the theme deck Charizard, Dark Blastoise, and Dark Raichu. I'm missing a few cards here and there through the e-card series, those being regualar rare cards and common/uncommon reverse holos (all the Crystal cards are present, including the reverse holos from the last e-card set). Have all the Wizards promos, as well as all the VS cards and about half of the Japanese promo cards and every half deck from the movie except for the Latias/Latios deck (I have the Latias and Latios, but nothing else).
I have no doubts that there are certainly other collectors and probably even some players that can rival or top what I have, but I am none the less proud of my collection